1. Field of the Invention
This invention relates to flashlights that utilize light-emitting diodes (LEDs) as a light source.
2. Description of the Related Art
The flashlight was invented in 1898 by Conrad Hubert who turned a metal tube, a light bulb and a battery into the world's first flashlight. Little has changed in flashlight technology since then. Today's flashlight technology is based on locating a tungsten lamp or bulb at the focus of a parabolic reflector and simply imaging the filament out into object space. The reflector may be of other shapes and may be faceted or otherwise modified. At a somewhat distant wall (such as at a distance of 3–6 feet for example) a crude image of the filament is formed.
A significant problem with the current flashlight technology is that the crude image (usually a circular spot) varies significantly in its intensity. While some flashlights permit the user to vary or adjust the size of the pattern, it is generally highly non-uniform in intensity over the spot. Another problem is that the light spills out to a wide area outside of the intended spot area.
Another problem is that the crude image cast by a conventional flashlight makes it difficult in many circumstances to clearly see the object of interest. This is because the variation in intensity over the illuminating spot can often mask or hide the features of the object of interest.
Another problem is that the illuminated area of prior art flashlights tends to be unattractive and unfamiliar. The illumination people generally experience in their daily lives is designed to be reasonably uniform and have sufficiently high brightness so that objects can be readily seen without eye strain. Unfortunately, conventional flashlights do not provide such illumination.